Heterologous rabbit anti-sera to human bladder carcinoma will be produced. These anti-sera will be used to demonstrate in gel-diffusion studies the presence of tumor-associated or specific antigens to bladder cancer. Anti-sera will be investigated for cross-reactivity with various other malignant and normal tissues. Specific absorption studies will be carried out to remove non-specific reactivity. Specific, absorbed heterologous anti-serum to bladder carcinoma will then be used in immunological assays (complement-fixation, Ouchterlony gel-diffusion) to detect human bladder cancer associated antigens in the urine of patients with bladder carcinoma, other urologic malignancy, other non-urological malignancy, other medical and surgical diseases and in normal healthy personnel. The incidence of bladder carcinoma associated antigen in the urine will be correlated with the presence of bladder cancer, its stage, type, differentiation, etc. and the feasibility of its detection by immunological means evaluated as a urinary screening test for bladder cancer.